git.oblomov.eu Git - linux-2.6/blob - drivers/char/tpm/tpm_atmel.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  *
   4  * Authors:
   5  * Leendert van Doorn <leendert@watson.ibm.com>
   6  * Dave Safford <safford@watson.ibm.com>
   7  * Reiner Sailer <sailer@watson.ibm.com>
   8  * Kylene Hall <kjhall@us.ibm.com>
   9  *
  10  * Maintained by: <tpmdd_devel@lists.sourceforge.net>
  11  *
  12  * Device driver for TCG/TCPA TPM (trusted platform module).
  13  * Specifications at www.trustedcomputinggroup.org
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License as
  17  * published by the Free Software Foundation, version 2 of the
  18  * License.
  19  *
  20  */
  21
  22 #include <linux/platform_device.h>
  23 #include "tpm.h"
  24
  25 /* Atmel definitions */
  26 enum tpm_atmel_addr {
  27         TPM_ATMEL_BASE_ADDR_LO = 0x08,
  28         TPM_ATMEL_BASE_ADDR_HI = 0x09
  29 };
  30
  31 /* write status bits */
  32 enum tpm_atmel_write_status {
  33         ATML_STATUS_ABORT = 0x01,
  34         ATML_STATUS_LASTBYTE = 0x04
  35 };
  36 /* read status bits */
  37 enum tpm_atmel_read_status {
  38         ATML_STATUS_BUSY = 0x01,
  39         ATML_STATUS_DATA_AVAIL = 0x02,
  40         ATML_STATUS_REWRITE = 0x04,
  41         ATML_STATUS_READY = 0x08
  42 };
  43
  44 static int tpm_atml_recv(struct tpm_chip *chip, u8 *buf, size_t count)
  45 {
  46         u8 status, *hdr = buf;
  47         u32 size;
  48         int i;
  49         __be32 *native_size;
  50
  51         /* start reading header */
  52         if (count < 6)
  53                 return -EIO;
  54
  55         for (i = 0; i < 6; i++) {
  56                 status = inb(chip->vendor->base + 1);
  57                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  58                         dev_err(chip->dev,
  59                                 "error reading header\n");
  60                         return -EIO;
  61                 }
  62                 *buf++ = inb(chip->vendor->base);
  63         }
  64
  65         /* size of the data received */
  66         native_size = (__force __be32 *) (hdr + 2);
  67         size = be32_to_cpu(*native_size);
  68
  69         if (count < size) {
  70                 dev_err(chip->dev,
  71                         "Recv size(%d) less than available space\n", size);
  72                 for (; i < size; i++) { /* clear the waiting data anyway */
  73                         status = inb(chip->vendor->base + 1);
  74                         if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  75                                 dev_err(chip->dev,
  76                                         "error reading data\n");
  77                                 return -EIO;
  78                         }
  79                 }
  80                 return -EIO;
  81         }
  82
  83         /* read all the data available */
  84         for (; i < size; i++) {
  85                 status = inb(chip->vendor->base + 1);
  86                 if ((status & ATML_STATUS_DATA_AVAIL) == 0) {
  87                         dev_err(chip->dev,
  88                                 "error reading data\n");
  89                         return -EIO;
  90                 }
  91                 *buf++ = inb(chip->vendor->base);
  92         }
  93
  94         /* make sure data available is gone */
  95         status = inb(chip->vendor->base + 1);
  96         if (status & ATML_STATUS_DATA_AVAIL) {
  97                 dev_err(chip->dev, "data available is stuck\n");
  98                 return -EIO;
  99         }
 100
 101         return size;
 102 }
 103
 104 static int tpm_atml_send(struct tpm_chip *chip, u8 *buf, size_t count)
 105 {
 106         int i;
 107
 108         dev_dbg(chip->dev, "tpm_atml_send:\n");
 109         for (i = 0; i < count; i++) {
 110                 dev_dbg(chip->dev, "%d 0x%x(%d)\n",  i, buf[i], buf[i]);
 111                 outb(buf[i], chip->vendor->base);
 112         }
 113
 114         return count;
 115 }
 116
 117 static void tpm_atml_cancel(struct tpm_chip *chip)
 118 {
 119         outb(ATML_STATUS_ABORT, chip->vendor->base + 1);
 120 }
 121
 122 static u8 tpm_atml_status(struct tpm_chip *chip)
 123 {
 124         return inb(chip->vendor->base + 1);
 125 }
 126
 127 static struct file_operations atmel_ops = {
 128         .owner = THIS_MODULE,
 129         .llseek = no_llseek,
 130         .open = tpm_open,
 131         .read = tpm_read,
 132         .write = tpm_write,
 133         .release = tpm_release,
 134 };
 135
 136 static DEVICE_ATTR(pubek, S_IRUGO, tpm_show_pubek, NULL);
 137 static DEVICE_ATTR(pcrs, S_IRUGO, tpm_show_pcrs, NULL);
 138 static DEVICE_ATTR(caps, S_IRUGO, tpm_show_caps, NULL);
 139 static DEVICE_ATTR(cancel, S_IWUSR |S_IWGRP, NULL, tpm_store_cancel);
 140
 141 static struct attribute* atmel_attrs[] = {
 142         &dev_attr_pubek.attr,
 143         &dev_attr_pcrs.attr,
 144         &dev_attr_caps.attr,
 145         &dev_attr_cancel.attr,
 146         NULL,
 147 };
 148
 149 static struct attribute_group atmel_attr_grp = { .attrs = atmel_attrs };
 150
 151 static struct tpm_vendor_specific tpm_atmel = {
 152         .recv = tpm_atml_recv,
 153         .send = tpm_atml_send,
 154         .cancel = tpm_atml_cancel,
 155         .status = tpm_atml_status,
 156         .req_complete_mask = ATML_STATUS_BUSY | ATML_STATUS_DATA_AVAIL,
 157         .req_complete_val = ATML_STATUS_DATA_AVAIL,
 158         .req_canceled = ATML_STATUS_READY,
 159         .attr_group = &atmel_attr_grp,
 160         .miscdev = { .fops = &atmel_ops, },
 161 };
 162
 163 static struct platform_device *pdev;
 164
 165 static void __devexit tpm_atml_remove(struct device *dev)
 166 {
 167         struct tpm_chip *chip = dev_get_drvdata(dev);
 168         if (chip) {
 169                 release_region(chip->vendor->base, 2);
 170                 tpm_remove_hardware(chip->dev);
 171         }
 172 }
 173
 174 static struct device_driver atml_drv = {
 175         .name = "tpm_atmel",
 176         .bus = &platform_bus_type,
 177         .owner = THIS_MODULE,
 178         .suspend = tpm_pm_suspend,
 179         .resume = tpm_pm_resume,
 180 };
 181
 182 static int __init init_atmel(void)
 183 {
 184         int rc = 0;
 185         int lo, hi;
 186
 187         driver_register(&atml_drv);
 188
 189         lo = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_LO);
 190         hi = tpm_read_index(TPM_ADDR, TPM_ATMEL_BASE_ADDR_HI);
 191
 192         tpm_atmel.base = (hi<<8)|lo;
 193
 194         /* verify that it is an Atmel part */
 195         if (tpm_read_index(TPM_ADDR, 4) != 'A' || tpm_read_index(TPM_ADDR, 5) != 'T'
 196             || tpm_read_index(TPM_ADDR, 6) != 'M' || tpm_read_index(TPM_ADDR, 7) != 'L') {
 197                 return -ENODEV;
 198         }
 199
 200         /* verify chip version number is 1.1 */
 201         if (    (tpm_read_index(TPM_ADDR, 0x00) != 0x01) ||
 202                 (tpm_read_index(TPM_ADDR, 0x01) != 0x01 ))
 203                 return -ENODEV;
 204
 205         pdev = kzalloc(sizeof(struct platform_device), GFP_KERNEL);
 206         if ( !pdev )
 207                 return -ENOMEM;
 208
 209         pdev->name = "tpm_atmel0";
 210         pdev->id = -1;
 211         pdev->num_resources = 0;
 212         pdev->dev.release = tpm_atml_remove;
 213         pdev->dev.driver = &atml_drv;
 214
 215         if ((rc = platform_device_register(pdev)) < 0) {
 216                 kfree(pdev);
 217                 pdev = NULL;
 218                 return rc;
 219         }
 220
 221         if (request_region(tpm_atmel.base, 2, "tpm_atmel0") == NULL ) {
 222                 platform_device_unregister(pdev);
 223                 kfree(pdev);
 224                 pdev = NULL;
 225                 return -EBUSY;
 226         }
 227
 228         if ((rc = tpm_register_hardware(&pdev->dev, &tpm_atmel)) < 0) {
 229                 release_region(tpm_atmel.base, 2);
 230                 platform_device_unregister(pdev);
 231                 kfree(pdev);
 232                 pdev = NULL;
 233                 return rc;
 234         }
 235
 236         dev_info(&pdev->dev, "Atmel TPM 1.1, Base Address: 0x%x\n",
 237                         tpm_atmel.base);
 238         return 0;
 239 }
 240
 241 static void __exit cleanup_atmel(void)
 242 {
 243         if (pdev) {
 244                 tpm_atml_remove(&pdev->dev);
 245                 platform_device_unregister(pdev);
 246                 kfree(pdev);
 247                 pdev = NULL;
 248         }
 249
 250         driver_unregister(&atml_drv);
 251 }
 252
 253 module_init(init_atmel);
 254 module_exit(cleanup_atmel);
 255
 256 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 257 MODULE_DESCRIPTION("TPM Driver");
 258 MODULE_VERSION("2.0");
 259 MODULE_LICENSE("GPL");